A joining element for joining two workpieces, which each are provided at the ends thereof with a groove, the grooves being aligned with one another for joining at the contact surfaces, has a disk-like configuration and is dimensioned such that it can be driven or stricken into the grooves. A point is added to a user member in accordance with the contents of the action of the member such as reception of an electronic mail from the mail delivery terminal 6 or transmission of a reply to a received electronic mail, and point information for each member is stored in the member registered information database 4. The hub defines a female luer sized to be received into and locked to the connector of the fluid system when the luer tip is advanced into the septum. The third-part software chooses the virtual play module and the virtual collect module.